drm_edid.c

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/*
 * Copyright (c) 2006 Luc Verhaegen (quirks list)
 * Copyright (c) 2007-2008 Intel Corporation
 *   Jesse Barnes <[email protected]>
 * Copyright 2010 Red Hat, Inc.
 *
 * DDC probing routines (drm_ddc_read & drm_do_probe_ddc_edid) originally from
 * FB layer.
 *   Copyright (C) 2006 Dennis Munsie <[email protected]>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sub license,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <drm/drmP.h>
#include <drm/drm_edid.h>
#include "drm_edid_modes.h"

#define version_greater(edid, maj, min) \
    (((edid)->version > (maj)) || \
     ((edid)->version == (maj) && (edid)->revision > (min)))

#define EDID_EST_TIMINGS 16
#define EDID_STD_TIMINGS 8
#define EDID_DETAILED_TIMINGS 4

/*
 * EDID blocks out in the wild have a variety of bugs, try to collect
 * them here (note that userspace may work around broken monitors first,
 * but fixes should make their way here so that the kernel "just works"
 * on as many displays as possible).
 */

/* First detailed mode wrong, use largest 60Hz mode */
#define EDID_QUIRK_PREFER_LARGE_60      (1 << 0)
/* Reported 135MHz pixel clock is too high, needs adjustment */
#define EDID_QUIRK_135_CLOCK_TOO_HIGH       (1 << 1)
/* Prefer the largest mode at 75 Hz */
#define EDID_QUIRK_PREFER_LARGE_75      (1 << 2)
/* Detail timing is in cm not mm */
#define EDID_QUIRK_DETAILED_IN_CM       (1 << 3)
/* Detailed timing descriptors have bogus size values, so just take the
 * maximum size and use that.
 */
#define EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE    (1 << 4)
/* Monitor forgot to set the first detailed is preferred bit. */
#define EDID_QUIRK_FIRST_DETAILED_PREFERRED (1 << 5)
/* use +hsync +vsync for detailed mode */
#define EDID_QUIRK_DETAILED_SYNC_PP     (1 << 6)
/* Force reduced-blanking timings for detailed modes */
#define EDID_QUIRK_FORCE_REDUCED_BLANKING   (1 << 7)

struct detailed_mode_closure {
    struct drm_connector *connector;
    struct edid *edid;
    bool preferred;
    u32 quirks;
    int modes;
};

#define LEVEL_DMT   0
#define LEVEL_GTF   1
#define LEVEL_GTF2  2
#define LEVEL_CVT   3

static struct edid_quirk {
    char vendor[4];
    int product_id;
    u32 quirks;
} edid_quirk_list[] = {
    /* ASUS VW222S */
    { "ACI", 0x22a2, EDID_QUIRK_FORCE_REDUCED_BLANKING },

    /* Acer AL1706 */
    { "ACR", 44358, EDID_QUIRK_PREFER_LARGE_60 },
    /* Acer F51 */
    { "API", 0x7602, EDID_QUIRK_PREFER_LARGE_60 },
    /* Unknown Acer */
    { "ACR", 2423, EDID_QUIRK_FIRST_DETAILED_PREFERRED },

    /* Belinea 10 15 55 */
    { "MAX", 1516, EDID_QUIRK_PREFER_LARGE_60 },
    { "MAX", 0x77e, EDID_QUIRK_PREFER_LARGE_60 },

    /* Envision Peripherals, Inc. EN-7100e */
    { "EPI", 59264, EDID_QUIRK_135_CLOCK_TOO_HIGH },
    /* Envision EN2028 */
    { "EPI", 8232, EDID_QUIRK_PREFER_LARGE_60 },

    /* Funai Electronics PM36B */
    { "FCM", 13600, EDID_QUIRK_PREFER_LARGE_75 |
      EDID_QUIRK_DETAILED_IN_CM },

    /* LG Philips LCD LP154W01-A5 */
    { "LPL", 0, EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE },
    { "LPL", 0x2a00, EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE },

    /* Philips 107p5 CRT */
    { "PHL", 57364, EDID_QUIRK_FIRST_DETAILED_PREFERRED },

    /* Proview AY765C */
    { "PTS", 765, EDID_QUIRK_FIRST_DETAILED_PREFERRED },

    /* Samsung SyncMaster 205BW.  Note: irony */
    { "SAM", 541, EDID_QUIRK_DETAILED_SYNC_PP },
    /* Samsung SyncMaster 22[5-6]BW */
    { "SAM", 596, EDID_QUIRK_PREFER_LARGE_60 },
    { "SAM", 638, EDID_QUIRK_PREFER_LARGE_60 },

    /* ViewSonic VA2026w */
    { "VSC", 5020, EDID_QUIRK_FORCE_REDUCED_BLANKING },
};

/*** DDC fetch and block validation ***/

static const u8 edid_header[] = {
    0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00
};

 /*
 * Sanity check the header of the base EDID block.  Return 8 if the header
 * is perfect, down to 0 if it's totally wrong.
 */
int drm_edid_header_is_valid(const u8 *raw_edid)
{
    int i, score = 0;

    for (i = 0; i < sizeof(edid_header); i++)
        if (raw_edid[i] == edid_header[i])
            score++;

    return score;
}
EXPORT_SYMBOL(drm_edid_header_is_valid);

static int edid_fixup __read_mostly = 6;
module_param_named(edid_fixup, edid_fixup, int, 0400);
MODULE_PARM_DESC(edid_fixup,
         "Minimum number of valid EDID header bytes (0-8, default 6)");

/*
 * Sanity check the EDID block (base or extension).  Return 0 if the block
 * doesn't check out, or 1 if it's valid.
 */
bool drm_edid_block_valid(u8 *raw_edid, int block, bool print_bad_edid)
{
    int i;
    u8 csum = 0;
    struct edid *edid = (struct edid *)raw_edid;

    if (edid_fixup > 8 || edid_fixup < 0)
        edid_fixup = 6;

    if (block == 0) {
        int score = drm_edid_header_is_valid(raw_edid);
        if (score == 8) ;
        else if (score >= edid_fixup) {
            DRM_DEBUG("Fixing EDID header, your hardware may be failing\n");
            memcpy(raw_edid, edid_header, sizeof(edid_header));
        } else {
            goto bad;
        }
    }

    for (i = 0; i < EDID_LENGTH; i++)
        csum += raw_edid[i];
    if (csum) {
        if (print_bad_edid) {
            DRM_ERROR("EDID checksum is invalid, remainder is %d\n", csum);
        }

        /* allow CEA to slide through, switches mangle this */
        if (raw_edid[0] != 0x02)
            goto bad;
    }

    /* per-block-type checks */
    switch (raw_edid[0]) {
    case 0: /* base */
        if (edid->version != 1) {
            DRM_ERROR("EDID has major version %d, instead of 1\n", edid->version);
            goto bad;
        }

        if (edid->revision > 4)
            DRM_DEBUG("EDID minor > 4, assuming backward compatibility\n");
        break;

    default:
        break;
    }

    return 1;

bad:
    if (raw_edid && print_bad_edid) {
        printk(KERN_ERR "Raw EDID:\n");
        print_hex_dump(KERN_ERR, " \t", DUMP_PREFIX_NONE, 16, 1,
                   raw_edid, EDID_LENGTH, false);
    }
    return 0;
}
EXPORT_SYMBOL(drm_edid_block_valid);

bool drm_edid_is_valid(struct edid *edid)
{
    int i;
    u8 *raw = (u8 *)edid;

    if (!edid)
        return false;

    for (i = 0; i <= edid->extensions; i++)
        if (!drm_edid_block_valid(raw + i * EDID_LENGTH, i, true))
            return false;

    return true;
}
EXPORT_SYMBOL(drm_edid_is_valid);

#define DDC_SEGMENT_ADDR 0x30

static int
drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf,
              int block, int len)
{
    unsigned char start = block * EDID_LENGTH;
    unsigned char segment = block >> 1;
    unsigned char xfers = segment ? 3 : 2;
    int ret, retries = 5;

    /* The core i2c driver will automatically retry the transfer if the
     * adapter reports EAGAIN. However, we find that bit-banging transfers
     * are susceptible to errors under a heavily loaded machine and
     * generate spurious NAKs and timeouts. Retrying the transfer
     * of the individual block a few times seems to overcome this.
     */
    do {
        struct i2c_msg msgs[] = {
            {
                .addr   = DDC_SEGMENT_ADDR,
                .flags  = 0,
                .len    = 1,
                .buf    = &segment,
            }, {
                .addr   = DDC_ADDR,
                .flags  = 0,
                .len    = 1,
                .buf    = &start,
            }, {
                .addr   = DDC_ADDR,
                .flags  = I2C_M_RD,
                .len    = len,
                .buf    = buf,
            }
        };

    /*
     * Avoid sending the segment addr to not upset non-compliant ddc
     * monitors.
     */
        ret = i2c_transfer(adapter, &msgs[3 - xfers], xfers);

        if (ret == -ENXIO) {
            DRM_DEBUG_KMS("drm: skipping non-existent adapter %s\n",
                    adapter->name);
            break;
        }
    } while (ret != xfers && --retries);

    return ret == xfers ? 0 : -1;
}

static bool drm_edid_is_zero(u8 *in_edid, int length)
{
    int i;
    u32 *raw_edid = (u32 *)in_edid;

    for (i = 0; i < length / 4; i++)
        if (*(raw_edid + i) != 0)
            return false;
    return true;
}

static u8 *
drm_do_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter)
{
    int i, j = 0, valid_extensions = 0;
    u8 *block, *new;
    bool print_bad_edid = !connector->bad_edid_counter || (drm_debug & DRM_UT_KMS);

    if ((block = kmalloc(EDID_LENGTH, GFP_KERNEL)) == NULL)
        return NULL;

    /* base block fetch */
    for (i = 0; i < 4; i++) {
        if (drm_do_probe_ddc_edid(adapter, block, 0, EDID_LENGTH))
            goto out;
        if (drm_edid_block_valid(block, 0, print_bad_edid))
            break;
        if (i == 0 && drm_edid_is_zero(block, EDID_LENGTH)) {
            connector->null_edid_counter++;
            goto carp;
        }
    }
    if (i == 4)
        goto carp;

    /* if there's no extensions, we're done */
    if (block[0x7e] == 0)
        return block;

    new = krealloc(block, (block[0x7e] + 1) * EDID_LENGTH, GFP_KERNEL);
    if (!new)
        goto out;
    block = new;

    for (j = 1; j <= block[0x7e]; j++) {
        for (i = 0; i < 4; i++) {
            if (drm_do_probe_ddc_edid(adapter,
                  block + (valid_extensions + 1) * EDID_LENGTH,
                  j, EDID_LENGTH))
                goto out;
            if (drm_edid_block_valid(block + (valid_extensions + 1) * EDID_LENGTH, j, print_bad_edid)) {
                valid_extensions++;
                break;
            }
        }
        if (i == 4)
            dev_warn(connector->dev->dev,
             "%s: Ignoring invalid EDID block %d.\n",
             drm_get_connector_name(connector), j);
    }

    if (valid_extensions != block[0x7e]) {
        block[EDID_LENGTH-1] += block[0x7e] - valid_extensions;
        block[0x7e] = valid_extensions;
        new = krealloc(block, (valid_extensions + 1) * EDID_LENGTH, GFP_KERNEL);
        if (!new)
            goto out;
        block = new;
    }

    return block;

carp:
    if (print_bad_edid) {
        dev_warn(connector->dev->dev, "%s: EDID block %d invalid.\n",
             drm_get_connector_name(connector), j);
    }
    connector->bad_edid_counter++;

out:
    kfree(block);
    return NULL;
}

bool
drm_probe_ddc(struct i2c_adapter *adapter)
{
    unsigned char out;

    return (drm_do_probe_ddc_edid(adapter, &out, 0, 1) == 0);
}
EXPORT_SYMBOL(drm_probe_ddc);

struct edid *drm_get_edid(struct drm_connector *connector,
              struct i2c_adapter *adapter)
{
    struct edid *edid = NULL;

    if (drm_probe_ddc(adapter))
        edid = (struct edid *)drm_do_get_edid(connector, adapter);

    return edid;
}
EXPORT_SYMBOL(drm_get_edid);

/*** EDID parsing ***/

static bool edid_vendor(struct edid *edid, char *vendor)
{
    char edid_vendor[3];

    edid_vendor[0] = ((edid->mfg_id[0] & 0x7c) >> 2) + '@';
    edid_vendor[1] = (((edid->mfg_id[0] & 0x3) << 3) |
              ((edid->mfg_id[1] & 0xe0) >> 5)) + '@';
    edid_vendor[2] = (edid->mfg_id[1] & 0x1f) + '@';

    return !strncmp(edid_vendor, vendor, 3);
}

static u32 edid_get_quirks(struct edid *edid)
{
    struct edid_quirk *quirk;
    int i;

    for (i = 0; i < ARRAY_SIZE(edid_quirk_list); i++) {
        quirk = &edid_quirk_list[i];

        if (edid_vendor(edid, quirk->vendor) &&
            (EDID_PRODUCT_ID(edid) == quirk->product_id))
            return quirk->quirks;
    }

    return 0;
}

#define MODE_SIZE(m) ((m)->hdisplay * (m)->vdisplay)
#define MODE_REFRESH_DIFF(m,r) (abs((m)->vrefresh - target_refresh))

static void edid_fixup_preferred(struct drm_connector *connector,
                 u32 quirks)
{
    struct drm_display_mode *t, *cur_mode, *preferred_mode;
    int target_refresh = 0;

    if (list_empty(&connector->probed_modes))
        return;

    if (quirks & EDID_QUIRK_PREFER_LARGE_60)
        target_refresh = 60;
    if (quirks & EDID_QUIRK_PREFER_LARGE_75)
        target_refresh = 75;

    preferred_mode = list_first_entry(&connector->probed_modes,
                      struct drm_display_mode, head);

    list_for_each_entry_safe(cur_mode, t, &connector->probed_modes, head) {
        cur_mode->type &= ~DRM_MODE_TYPE_PREFERRED;

        if (cur_mode == preferred_mode)
            continue;

        /* Largest mode is preferred */
        if (MODE_SIZE(cur_mode) > MODE_SIZE(preferred_mode))
            preferred_mode = cur_mode;

        /* At a given size, try to get closest to target refresh */
        if ((MODE_SIZE(cur_mode) == MODE_SIZE(preferred_mode)) &&
            MODE_REFRESH_DIFF(cur_mode, target_refresh) <
            MODE_REFRESH_DIFF(preferred_mode, target_refresh)) {
            preferred_mode = cur_mode;
        }
    }

    preferred_mode->type |= DRM_MODE_TYPE_PREFERRED;
}

static bool
mode_is_rb(const struct drm_display_mode *mode)
{
    return (mode->htotal - mode->hdisplay == 160) &&
           (mode->hsync_end - mode->hdisplay == 80) &&
           (mode->hsync_end - mode->hsync_start == 32) &&
           (mode->vsync_start - mode->vdisplay == 3);
}

/*
 * drm_mode_find_dmt - Create a copy of a mode if present in DMT
 * @dev: Device to duplicate against
 * @hsize: Mode width
 * @vsize: Mode height
 * @fresh: Mode refresh rate
 * @rb: Mode reduced-blanking-ness
 *
 * Walk the DMT mode list looking for a match for the given parameters.
 * Return a newly allocated copy of the mode, or NULL if not found.
 */
struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
                       int hsize, int vsize, int fresh,
                       bool rb)
{
    int i;

    for (i = 0; i < drm_num_dmt_modes; i++) {
        const struct drm_display_mode *ptr = &drm_dmt_modes[i];
        if (hsize != ptr->hdisplay)
            continue;
        if (vsize != ptr->vdisplay)
            continue;
        if (fresh != drm_mode_vrefresh(ptr))
            continue;
        if (rb != mode_is_rb(ptr))
            continue;

        return drm_mode_duplicate(dev, ptr);
    }

    return NULL;
}
EXPORT_SYMBOL(drm_mode_find_dmt);

typedef void detailed_cb(struct detailed_timing *timing, void *closure);

static void
cea_for_each_detailed_block(u8 *ext, detailed_cb *cb, void *closure)
{
    int i, n = 0;
    u8 d = ext[0x02];
    u8 *det_base = ext + d;

    n = (127 - d) / 18;
    for (i = 0; i < n; i++)
        cb((struct detailed_timing *)(det_base + 18 * i), closure);
}

static void
vtb_for_each_detailed_block(u8 *ext, detailed_cb *cb, void *closure)
{
    unsigned int i, n = min((int)ext[0x02], 6);
    u8 *det_base = ext + 5;

    if (ext[0x01] != 1)
        return; /* unknown version */

    for (i = 0; i < n; i++)
        cb((struct detailed_timing *)(det_base + 18 * i), closure);
}

static void
drm_for_each_detailed_block(u8 *raw_edid, detailed_cb *cb, void *closure)
{
    int i;
    struct edid *edid = (struct edid *)raw_edid;

    if (edid == NULL)
        return;

    for (i = 0; i < EDID_DETAILED_TIMINGS; i++)
        cb(&(edid->detailed_timings[i]), closure);

    for (i = 1; i <= raw_edid[0x7e]; i++) {
        u8 *ext = raw_edid + (i * EDID_LENGTH);
        switch (*ext) {
        case CEA_EXT:
            cea_for_each_detailed_block(ext, cb, closure);
            break;
        case VTB_EXT:
            vtb_for_each_detailed_block(ext, cb, closure);
            break;
        default:
            break;
        }
    }
}

static void
is_rb(struct detailed_timing *t, void *data)
{
    u8 *r = (u8 *)t;
    if (r[3] == EDID_DETAIL_MONITOR_RANGE)
        if (r[15] & 0x10)
            *(bool *)data = true;
}

/* EDID 1.4 defines this explicitly.  For EDID 1.3, we guess, badly. */
static bool
drm_monitor_supports_rb(struct edid *edid)
{
    if (edid->revision >= 4) {
        bool ret = false;
        drm_for_each_detailed_block((u8 *)edid, is_rb, &ret);
        return ret;
    }

    return ((edid->input & DRM_EDID_INPUT_DIGITAL) != 0);
}

static void
find_gtf2(struct detailed_timing *t, void *data)
{
    u8 *r = (u8 *)t;
    if (r[3] == EDID_DETAIL_MONITOR_RANGE && r[10] == 0x02)
        *(u8 **)data = r;
}

/* Secondary GTF curve kicks in above some break frequency */
static int
drm_gtf2_hbreak(struct edid *edid)
{
    u8 *r = NULL;
    drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
    return r ? (r[12] * 2) : 0;
}

static int
drm_gtf2_2c(struct edid *edid)
{
    u8 *r = NULL;
    drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
    return r ? r[13] : 0;
}

static int
drm_gtf2_m(struct edid *edid)
{
    u8 *r = NULL;
    drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
    return r ? (r[15] << 8) + r[14] : 0;
}

static int
drm_gtf2_k(struct edid *edid)
{
    u8 *r = NULL;
    drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
    return r ? r[16] : 0;
}

static int
drm_gtf2_2j(struct edid *edid)
{
    u8 *r = NULL;
    drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
    return r ? r[17] : 0;
}

static int standard_timing_level(struct edid *edid)
{
    if (edid->revision >= 2) {
        if (edid->revision >= 4 && (edid->features & DRM_EDID_FEATURE_DEFAULT_GTF))
            return LEVEL_CVT;
        if (drm_gtf2_hbreak(edid))
            return LEVEL_GTF2;
        return LEVEL_GTF;
    }
    return LEVEL_DMT;
}

/*
 * 0 is reserved.  The spec says 0x01 fill for unused timings.  Some old
 * monitors fill with ascii space (0x20) instead.
 */
static int
bad_std_timing(u8 a, u8 b)
{
    return (a == 0x00 && b == 0x00) ||
           (a == 0x01 && b == 0x01) ||
           (a == 0x20 && b == 0x20);
}

static struct drm_display_mode *
drm_mode_std(struct drm_connector *connector, struct edid *edid,
         struct std_timing *t, int revision)
{
    struct drm_device *dev = connector->dev;
    struct drm_display_mode *m, *mode = NULL;
    int hsize, vsize;
    int vrefresh_rate;
    unsigned aspect_ratio = (t->vfreq_aspect & EDID_TIMING_ASPECT_MASK)
        >> EDID_TIMING_ASPECT_SHIFT;
    unsigned vfreq = (t->vfreq_aspect & EDID_TIMING_VFREQ_MASK)
        >> EDID_TIMING_VFREQ_SHIFT;
    int timing_level = standard_timing_level(edid);

    if (bad_std_timing(t->hsize, t->vfreq_aspect))
        return NULL;

    /* According to the EDID spec, the hdisplay = hsize * 8 + 248 */
    hsize = t->hsize * 8 + 248;
    /* vrefresh_rate = vfreq + 60 */
    vrefresh_rate = vfreq + 60;
    /* the vdisplay is calculated based on the aspect ratio */
    if (aspect_ratio == 0) {
        if (revision < 3)
            vsize = hsize;
        else
            vsize = (hsize * 10) / 16;
    } else if (aspect_ratio == 1)
        vsize = (hsize * 3) / 4;
    else if (aspect_ratio == 2)
        vsize = (hsize * 4) / 5;
    else
        vsize = (hsize * 9) / 16;

    /* HDTV hack, part 1 */
    if (vrefresh_rate == 60 &&
        ((hsize == 1360 && vsize == 765) ||
         (hsize == 1368 && vsize == 769))) {
        hsize = 1366;
        vsize = 768;
    }

    /*
     * If this connector already has a mode for this size and refresh
     * rate (because it came from detailed or CVT info), use that
     * instead.  This way we don't have to guess at interlace or
     * reduced blanking.
     */
    list_for_each_entry(m, &connector->probed_modes, head)
        if (m->hdisplay == hsize && m->vdisplay == vsize &&
            drm_mode_vrefresh(m) == vrefresh_rate)
            return NULL;

    /* HDTV hack, part 2 */
    if (hsize == 1366 && vsize == 768 && vrefresh_rate == 60) {
        mode = drm_cvt_mode(dev, 1366, 768, vrefresh_rate, 0, 0,
                    false);
        mode->hdisplay = 1366;
        mode->hsync_start = mode->hsync_start - 1;
        mode->hsync_end = mode->hsync_end - 1;
        return mode;
    }

    /* check whether it can be found in default mode table */
    if (drm_monitor_supports_rb(edid)) {
        mode = drm_mode_find_dmt(dev, hsize, vsize, vrefresh_rate,
                     true);
        if (mode)
            return mode;
    }
    mode = drm_mode_find_dmt(dev, hsize, vsize, vrefresh_rate, false);
    if (mode)
        return mode;

    /* okay, generate it */
    switch (timing_level) {
    case LEVEL_DMT:
        break;
    case LEVEL_GTF:
        mode = drm_gtf_mode(dev, hsize, vsize, vrefresh_rate, 0, 0);
        break;
    case LEVEL_GTF2:
        /*
         * This is potentially wrong if there's ever a monitor with
         * more than one ranges section, each claiming a different
         * secondary GTF curve.  Please don't do that.
         */
        mode = drm_gtf_mode(dev, hsize, vsize, vrefresh_rate, 0, 0);
        if (!mode)
            return NULL;
        if (drm_mode_hsync(mode) > drm_gtf2_hbreak(edid)) {
            drm_mode_destroy(dev, mode);
            mode = drm_gtf_mode_complex(dev, hsize, vsize,
                            vrefresh_rate, 0, 0,
                            drm_gtf2_m(edid),
                            drm_gtf2_2c(edid),
                            drm_gtf2_k(edid),
                            drm_gtf2_2j(edid));
        }
        break;
    case LEVEL_CVT:
        mode = drm_cvt_mode(dev, hsize, vsize, vrefresh_rate, 0, 0,
                    false);
        break;
    }
    return mode;
}

/*
 * EDID is delightfully ambiguous about how interlaced modes are to be
 * encoded.  Our internal representation is of frame height, but some
 * HDTV detailed timings are encoded as field height.
 *
 * The format list here is from CEA, in frame size.  Technically we
 * should be checking refresh rate too.  Whatever.
 */
static void
drm_mode_do_interlace_quirk(struct drm_display_mode *mode,
                struct detailed_pixel_timing *pt)
{
    int i;
    static const struct {
        int w, h;
    } cea_interlaced[] = {
        { 1920, 1080 },
        {  720,  480 },
        { 1440,  480 },
        { 2880,  480 },
        {  720,  576 },
        { 1440,  576 },
        { 2880,  576 },
    };

    if (!(pt->misc & DRM_EDID_PT_INTERLACED))
        return;

    for (i = 0; i < ARRAY_SIZE(cea_interlaced); i++) {
        if ((mode->hdisplay == cea_interlaced[i].w) &&
            (mode->vdisplay == cea_interlaced[i].h / 2)) {
            mode->vdisplay *= 2;
            mode->vsync_start *= 2;
            mode->vsync_end *= 2;
            mode->vtotal *= 2;
            mode->vtotal |= 1;
        }
    }

    mode->flags |= DRM_MODE_FLAG_INTERLACE;
}

static struct drm_display_mode *drm_mode_detailed(struct drm_device *dev,
                          struct edid *edid,
                          struct detailed_timing *timing,
                          u32 quirks)
{
    struct drm_display_mode *mode;
    struct detailed_pixel_timing *pt = &timing->data.pixel_data;
    unsigned hactive = (pt->hactive_hblank_hi & 0xf0) << 4 | pt->hactive_lo;
    unsigned vactive = (pt->vactive_vblank_hi & 0xf0) << 4 | pt->vactive_lo;
    unsigned hblank = (pt->hactive_hblank_hi & 0xf) << 8 | pt->hblank_lo;
    unsigned vblank = (pt->vactive_vblank_hi & 0xf) << 8 | pt->vblank_lo;
    unsigned hsync_offset = (pt->hsync_vsync_offset_pulse_width_hi & 0xc0) << 2 | pt->hsync_offset_lo;
    unsigned hsync_pulse_width = (pt->hsync_vsync_offset_pulse_width_hi & 0x30) << 4 | pt->hsync_pulse_width_lo;
    unsigned vsync_offset = (pt->hsync_vsync_offset_pulse_width_hi & 0xc) >> 2 | pt->vsync_offset_pulse_width_lo >> 4;
    unsigned vsync_pulse_width = (pt->hsync_vsync_offset_pulse_width_hi & 0x3) << 4 | (pt->vsync_offset_pulse_width_lo & 0xf);

    /* ignore tiny modes */
    if (hactive < 64 || vactive < 64)
        return NULL;

    if (pt->misc & DRM_EDID_PT_STEREO) {
        printk(KERN_WARNING "stereo mode not supported\n");
        return NULL;
    }
    if (!(pt->misc & DRM_EDID_PT_SEPARATE_SYNC)) {
        printk(KERN_WARNING "composite sync not supported\n");
    }

    /* it is incorrect if hsync/vsync width is zero */
    if (!hsync_pulse_width || !vsync_pulse_width) {
        DRM_DEBUG_KMS("Incorrect Detailed timing. "
                "Wrong Hsync/Vsync pulse width\n");
        return NULL;
    }

    if (quirks & EDID_QUIRK_FORCE_REDUCED_BLANKING) {
        mode = drm_cvt_mode(dev, hactive, vactive, 60, true, false, false);
        if (!mode)
            return NULL;

        goto set_size;
    }

    mode = drm_mode_create(dev);
    if (!mode)
        return NULL;

    if (quirks & EDID_QUIRK_135_CLOCK_TOO_HIGH)
        timing->pixel_clock = cpu_to_le16(1088);

    mode->clock = le16_to_cpu(timing->pixel_clock) * 10;

    mode->hdisplay = hactive;
    mode->hsync_start = mode->hdisplay + hsync_offset;
    mode->hsync_end = mode->hsync_start + hsync_pulse_width;
    mode->htotal = mode->hdisplay + hblank;

    mode->vdisplay = vactive;
    mode->vsync_start = mode->vdisplay + vsync_offset;
    mode->vsync_end = mode->vsync_start + vsync_pulse_width;
    mode->vtotal = mode->vdisplay + vblank;

    /* Some EDIDs have bogus h/vtotal values */
    if (mode->hsync_end > mode->htotal)
        mode->htotal = mode->hsync_end + 1;
    if (mode->vsync_end > mode->vtotal)
        mode->vtotal = mode->vsync_end + 1;

    drm_mode_do_interlace_quirk(mode, pt);

    if (quirks & EDID_QUIRK_DETAILED_SYNC_PP) {
        pt->misc |= DRM_EDID_PT_HSYNC_POSITIVE | DRM_EDID_PT_VSYNC_POSITIVE;
    }

    mode->flags |= (pt->misc & DRM_EDID_PT_HSYNC_POSITIVE) ?
        DRM_MODE_FLAG_PHSYNC : DRM_MODE_FLAG_NHSYNC;
    mode->flags |= (pt->misc & DRM_EDID_PT_VSYNC_POSITIVE) ?
        DRM_MODE_FLAG_PVSYNC : DRM_MODE_FLAG_NVSYNC;

set_size:
    mode->width_mm = pt->width_mm_lo | (pt->width_height_mm_hi & 0xf0) << 4;
    mode->height_mm = pt->height_mm_lo | (pt->width_height_mm_hi & 0xf) << 8;

    if (quirks & EDID_QUIRK_DETAILED_IN_CM) {
        mode->width_mm *= 10;
        mode->height_mm *= 10;
    }

    if (quirks & EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE) {
        mode->width_mm = edid->width_cm * 10;
        mode->height_mm = edid->height_cm * 10;
    }

    mode->type = DRM_MODE_TYPE_DRIVER;
    drm_mode_set_name(mode);

    return mode;
}

static bool
mode_in_hsync_range(const struct drm_display_mode *mode,
            struct edid *edid, u8 *t)
{
    int hsync, hmin, hmax;

    hmin = t[7];
    if (edid->revision >= 4)
        hmin += ((t[4] & 0x04) ? 255 : 0);
    hmax = t[8];
    if (edid->revision >= 4)
        hmax += ((t[4] & 0x08) ? 255 : 0);
    hsync = drm_mode_hsync(mode);

    return (hsync <= hmax && hsync >= hmin);
}

static bool
mode_in_vsync_range(const struct drm_display_mode *mode,
            struct edid *edid, u8 *t)
{
    int vsync, vmin, vmax;

    vmin = t[5];
    if (edid->revision >= 4)
        vmin += ((t[4] & 0x01) ? 255 : 0);
    vmax = t[6];
    if (edid->revision >= 4)
        vmax += ((t[4] & 0x02) ? 255 : 0);
    vsync = drm_mode_vrefresh(mode);

    return (vsync <= vmax && vsync >= vmin);
}

static u32
range_pixel_clock(struct edid *edid, u8 *t)
{
    /* unspecified */
    if (t[9] == 0 || t[9] == 255)
        return 0;

    /* 1.4 with CVT support gives us real precision, yay */
    if (edid->revision >= 4 && t[10] == 0x04)
        return (t[9] * 10000) - ((t[12] >> 2) * 250);

    /* 1.3 is pathetic, so fuzz up a bit */
    return t[9] * 10000 + 5001;
}

static bool
mode_in_range(const struct drm_display_mode *mode, struct edid *edid,
          struct detailed_timing *timing)
{
    u32 max_clock;
    u8 *t = (u8 *)timing;

    if (!mode_in_hsync_range(mode, edid, t))
        return false;

    if (!mode_in_vsync_range(mode, edid, t))
        return false;

    if ((max_clock = range_pixel_clock(edid, t)))
        if (mode->clock > max_clock)
            return false;

    /* 1.4 max horizontal check */
    if (edid->revision >= 4 && t[10] == 0x04)
        if (t[13] && mode->hdisplay > 8 * (t[13] + (256 * (t[12]&0x3))))
            return false;

    if (mode_is_rb(mode) && !drm_monitor_supports_rb(edid))
        return false;

    return true;
}

static bool valid_inferred_mode(const struct drm_connector *connector,
                const struct drm_display_mode *mode)
{
    struct drm_display_mode *m;
    bool ok = false;

    list_for_each_entry(m, &connector->probed_modes, head) {
        if (mode->hdisplay == m->hdisplay &&
            mode->vdisplay == m->vdisplay &&
            drm_mode_vrefresh(mode) == drm_mode_vrefresh(m))
            return false; /* duplicated */
        if (mode->hdisplay <= m->hdisplay &&
            mode->vdisplay <= m->vdisplay)
            ok = true;
    }
    return ok;
}

static int
drm_dmt_modes_for_range(struct drm_connector *connector, struct edid *edid,
            struct detailed_timing *timing)
{
    int i, modes = 0;
    struct drm_display_mode *newmode;
    struct drm_device *dev = connector->dev;

    for (i = 0; i < drm_num_dmt_modes; i++) {
        if (mode_in_range(drm_dmt_modes + i, edid, timing) &&
            valid_inferred_mode(connector, drm_dmt_modes + i)) {
            newmode = drm_mode_duplicate(dev, &drm_dmt_modes[i]);
            if (newmode) {
                drm_mode_probed_add(connector, newmode);
                modes++;
            }
        }
    }

    return modes;
}

/* fix up 1366x768 mode from 1368x768;
 * GFT/CVT can't express 1366 width which isn't dividable by 8
 */
static void fixup_mode_1366x768(struct drm_display_mode *mode)
{
    if (mode->hdisplay == 1368 && mode->vdisplay == 768) {
        mode->hdisplay = 1366;
        mode->hsync_start--;
        mode->hsync_end--;
        drm_mode_set_name(mode);
    }
}

static int
drm_gtf_modes_for_range(struct drm_connector *connector, struct edid *edid,
            struct detailed_timing *timing)
{
    int i, modes = 0;
    struct drm_display_mode *newmode;
    struct drm_device *dev = connector->dev;

    for (i = 0; i < num_extra_modes; i++) {
        const struct minimode *m = &extra_modes[i];
        newmode = drm_gtf_mode(dev, m->w, m->h, m->r, 0, 0);
        if (!newmode)
            return modes;

        fixup_mode_1366x768(newmode);
        if (!mode_in_range(newmode, edid, timing) ||
            !valid_inferred_mode(connector, newmode)) {
            drm_mode_destroy(dev, newmode);
            continue;
        }

        drm_mode_probed_add(connector, newmode);
        modes++;
    }

    return modes;
}

static int
drm_cvt_modes_for_range(struct drm_connector *connector, struct edid *edid,
            struct detailed_timing *timing)
{
    int i, modes = 0;
    struct drm_display_mode *newmode;
    struct drm_device *dev = connector->dev;
    bool rb = drm_monitor_supports_rb(edid);

    for (i = 0; i < num_extra_modes; i++) {
        const struct minimode *m = &extra_modes[i];
        newmode = drm_cvt_mode(dev, m->w, m->h, m->r, rb, 0, 0);
        if (!newmode)
            return modes;

        fixup_mode_1366x768(newmode);
        if (!mode_in_range(newmode, edid, timing) ||
            !valid_inferred_mode(connector, newmode)) {
            drm_mode_destroy(dev, newmode);
            continue;
        }

        drm_mode_probed_add(connector, newmode);
        modes++;
    }

    return modes;
}

static void
do_inferred_modes(struct detailed_timing *timing, void *c)
{
    struct detailed_mode_closure *closure = c;
    struct detailed_non_pixel *data = &timing->data.other_data;
    struct detailed_data_monitor_range *range = &data->data.range;

    if (data->type != EDID_DETAIL_MONITOR_RANGE)
        return;

    closure->modes += drm_dmt_modes_for_range(closure->connector,
                          closure->edid,
                          timing);
    
    if (!version_greater(closure->edid, 1, 1))
        return; /* GTF not defined yet */

    switch (range->flags) {
    case 0x02: /* secondary gtf, XXX could do more */
    case 0x00: /* default gtf */
        closure->modes += drm_gtf_modes_for_range(closure->connector,
                              closure->edid,
                              timing);
        break;
    case 0x04: /* cvt, only in 1.4+ */
        if (!version_greater(closure->edid, 1, 3))
            break;

        closure->modes += drm_cvt_modes_for_range(closure->connector,
                              closure->edid,
                              timing);
        break;
    case 0x01: /* just the ranges, no formula */
    default:
        break;
    }
}

static int
add_inferred_modes(struct drm_connector *connector, struct edid *edid)
{
    struct detailed_mode_closure closure = {
        connector, edid, 0, 0, 0
    };

    if (version_greater(edid, 1, 0))
        drm_for_each_detailed_block((u8 *)edid, do_inferred_modes,
                        &closure);

    return closure.modes;
}

static int
drm_est3_modes(struct drm_connector *connector, struct detailed_timing *timing)
{
    int i, j, m, modes = 0;
    struct drm_display_mode *mode;
    u8 *est = ((u8 *)timing) + 5;

    for (i = 0; i < 6; i++) {
        for (j = 7; j > 0; j--) {
            m = (i * 8) + (7 - j);
            if (m >= ARRAY_SIZE(est3_modes))
                break;
            if (est[i] & (1 << j)) {
                mode = drm_mode_find_dmt(connector->dev,
                             est3_modes[m].w,
                             est3_modes[m].h,
                             est3_modes[m].r,
                             est3_modes[m].rb);
                if (mode) {
                    drm_mode_probed_add(connector, mode);
                    modes++;
                }
            }
        }
    }

    return modes;
}

static void
do_established_modes(struct detailed_timing *timing, void *c)
{
    struct detailed_mode_closure *closure = c;
    struct detailed_non_pixel *data = &timing->data.other_data;

    if (data->type == EDID_DETAIL_EST_TIMINGS)
        closure->modes += drm_est3_modes(closure->connector, timing);
}

static int
add_established_modes(struct drm_connector *connector, struct edid *edid)
{
    struct drm_device *dev = connector->dev;
    unsigned long est_bits = edid->established_timings.t1 |
        (edid->established_timings.t2 << 8) |
        ((edid->established_timings.mfg_rsvd & 0x80) << 9);
    int i, modes = 0;
    struct detailed_mode_closure closure = {
        connector, edid, 0, 0, 0
    };

    for (i = 0; i <= EDID_EST_TIMINGS; i++) {
        if (est_bits & (1<<i)) {
            struct drm_display_mode *newmode;
            newmode = drm_mode_duplicate(dev, &edid_est_modes[i]);
            if (newmode) {
                drm_mode_probed_add(connector, newmode);
                modes++;
            }
        }
    }

    if (version_greater(edid, 1, 0))
            drm_for_each_detailed_block((u8 *)edid,
                        do_established_modes, &closure);

    return modes + closure.modes;
}

static void
do_standard_modes(struct detailed_timing *timing, void *c)
{
    struct detailed_mode_closure *closure = c;
    struct detailed_non_pixel *data = &timing->data.other_data;
    struct drm_connector *connector = closure->connector;
    struct edid *edid = closure->edid;

    if (data->type == EDID_DETAIL_STD_MODES) {
        int i;
        for (i = 0; i < 6; i++) {
            struct std_timing *std;
            struct drm_display_mode *newmode;

            std = &data->data.timings[i];
            newmode = drm_mode_std(connector, edid, std,
                           edid->revision);
            if (newmode) {
                drm_mode_probed_add(connector, newmode);
                closure->modes++;
            }
        }
    }
}

static int
add_standard_modes(struct drm_connector *connector, struct edid *edid)
{
    int i, modes = 0;
    struct detailed_mode_closure closure = {
        connector, edid, 0, 0, 0
    };

    for (i = 0; i < EDID_STD_TIMINGS; i++) {
        struct drm_display_mode *newmode;

        newmode = drm_mode_std(connector, edid,
                       &edid->standard_timings[i],
                       edid->revision);
        if (newmode) {
            drm_mode_probed_add(connector, newmode);
            modes++;
        }
    }

    if (version_greater(edid, 1, 0))
        drm_for_each_detailed_block((u8 *)edid, do_standard_modes,
                        &closure);

    /* XXX should also look for standard codes in VTB blocks */

    return modes + closure.modes;
}

static int drm_cvt_modes(struct drm_connector *connector,
             struct detailed_timing *timing)
{
    int i, j, modes = 0;
    struct drm_display_mode *newmode;
    struct drm_device *dev = connector->dev;
    struct cvt_timing *cvt;
    const int rates[] = { 60, 85, 75, 60, 50 };
    const u8 empty[3] = { 0, 0, 0 };

    for (i = 0; i < 4; i++) {
        int uninitialized_var(width), height;
        cvt = &(timing->data.other_data.data.cvt[i]);

        if (!memcmp(cvt->code, empty, 3))
            continue;

        height = (cvt->code[0] + ((cvt->code[1] & 0xf0) << 4) + 1) * 2;
        switch (cvt->code[1] & 0x0c) {
        case 0x00:
            width = height * 4 / 3;
            break;
        case 0x04:
            width = height * 16 / 9;
            break;
        case 0x08:
            width = height * 16 / 10;
            break;
        case 0x0c:
            width = height * 15 / 9;
            break;
        }

        for (j = 1; j < 5; j++) {
            if (cvt->code[2] & (1 << j)) {
                newmode = drm_cvt_mode(dev, width, height,
                               rates[j], j == 0,
                               false, false);
                if (newmode) {
                    drm_mode_probed_add(connector, newmode);
                    modes++;
                }
            }
        }
    }

    return modes;
}

static void
do_cvt_mode(struct detailed_timing *timing, void *c)
{
    struct detailed_mode_closure *closure = c;
    struct detailed_non_pixel *data = &timing->data.other_data;

    if (data->type == EDID_DETAIL_CVT_3BYTE)
        closure->modes += drm_cvt_modes(closure->connector, timing);
}

static int
add_cvt_modes(struct drm_connector *connector, struct edid *edid)
{   
    struct detailed_mode_closure closure = {
        connector, edid, 0, 0, 0
    };

    if (version_greater(edid, 1, 2))
        drm_for_each_detailed_block((u8 *)edid, do_cvt_mode, &closure);

    /* XXX should also look for CVT codes in VTB blocks */

    return closure.modes;
}

static void
do_detailed_mode(struct detailed_timing *timing, void *c)
{
    struct detailed_mode_closure *closure = c;
    struct drm_display_mode *newmode;

    if (timing->pixel_clock) {
        newmode = drm_mode_detailed(closure->connector->dev,
                        closure->edid, timing,
                        closure->quirks);
        if (!newmode)
            return;

        if (closure->preferred)
            newmode->type |= DRM_MODE_TYPE_PREFERRED;

        drm_mode_probed_add(closure->connector, newmode);
        closure->modes++;
        closure->preferred = 0;
    }
}

/*
 * add_detailed_modes - Add modes from detailed timings
 * @connector: attached connector
 * @edid: EDID block to scan
 * @quirks: quirks to apply
 */
static int
add_detailed_modes(struct drm_connector *connector, struct edid *edid,
           u32 quirks)
{
    struct detailed_mode_closure closure = {
        connector,
        edid,
        1,
        quirks,
        0
    };

    if (closure.preferred && !version_greater(edid, 1, 3))
        closure.preferred =
            (edid->features & DRM_EDID_FEATURE_PREFERRED_TIMING);

    drm_for_each_detailed_block((u8 *)edid, do_detailed_mode, &closure);

    return closure.modes;
}

#define HDMI_IDENTIFIER 0x000C03
#define AUDIO_BLOCK 0x01
#define VIDEO_BLOCK     0x02
#define VENDOR_BLOCK    0x03
#define SPEAKER_BLOCK   0x04
#define EDID_BASIC_AUDIO    (1 << 6)
#define EDID_CEA_YCRCB444   (1 << 5)
#define EDID_CEA_YCRCB422   (1 << 4)

u8 *drm_find_cea_extension(struct edid *edid)
{
    u8 *edid_ext = NULL;
    int i;

    /* No EDID or EDID extensions */
    if (edid == NULL || edid->extensions == 0)
        return NULL;

    /* Find CEA extension */
    for (i = 0; i < edid->extensions; i++) {
        edid_ext = (u8 *)edid + EDID_LENGTH * (i + 1);
        if (edid_ext[0] == CEA_EXT)
            break;
    }

    if (i == edid->extensions)
        return NULL;

    return edid_ext;
}
EXPORT_SYMBOL(drm_find_cea_extension);

static int
do_cea_modes (struct drm_connector *connector, u8 *db, u8 len)
{
    struct drm_device *dev = connector->dev;
    u8 * mode, cea_mode;
    int modes = 0;

    for (mode = db; mode < db + len; mode++) {
        cea_mode = (*mode & 127) - 1; /* CEA modes are numbered 1..127 */
        if (cea_mode < drm_num_cea_modes) {
            struct drm_display_mode *newmode;
            newmode = drm_mode_duplicate(dev,
                             &edid_cea_modes[cea_mode]);
            if (newmode) {
                drm_mode_probed_add(connector, newmode);
                modes++;
            }
        }
    }

    return modes;
}

static int
cea_db_payload_len(const u8 *db)
{
    return db[0] & 0x1f;
}

static int
cea_db_tag(const u8 *db)
{
    return db[0] >> 5;
}

static int
cea_revision(const u8 *cea)
{
    return cea[1];
}

static int
cea_db_offsets(const u8 *cea, int *start, int *end)
{
    /* Data block offset in CEA extension block */
    *start = 4;
    *end = cea[2];
    if (*end == 0)
        *end = 127;
    if (*end < 4 || *end > 127)
        return -ERANGE;
    return 0;
}

#define for_each_cea_db(cea, i, start, end) \
    for ((i) = (start); (i) < (end) && (i) + cea_db_payload_len(&(cea)[(i)]) < (end); (i) += cea_db_payload_len(&(cea)[(i)]) + 1)

static int
add_cea_modes(struct drm_connector *connector, struct edid *edid)
{
    u8 * cea = drm_find_cea_extension(edid);
    u8 * db, dbl;
    int modes = 0;

    if (cea && cea_revision(cea) >= 3) {
        int i, start, end;

        if (cea_db_offsets(cea, &start, &end))
            return 0;

        for_each_cea_db(cea, i, start, end) {
            db = &cea[i];
            dbl = cea_db_payload_len(db);

            if (cea_db_tag(db) == VIDEO_BLOCK)
                modes += do_cea_modes (connector, db+1, dbl);
        }
    }

    return modes;
}

static void
parse_hdmi_vsdb(struct drm_connector *connector, const u8 *db)
{
    u8 len = cea_db_payload_len(db);

    if (len >= 6) {
        connector->eld[5] |= (db[6] >> 7) << 1;  /* Supports_AI */
        connector->dvi_dual = db[6] & 1;
    }
    if (len >= 7)
        connector->max_tmds_clock = db[7] * 5;
    if (len >= 8) {
        connector->latency_present[0] = db[8] >> 7;
        connector->latency_present[1] = (db[8] >> 6) & 1;
    }
    if (len >= 9)
        connector->video_latency[0] = db[9];
    if (len >= 10)
        connector->audio_latency[0] = db[10];
    if (len >= 11)
        connector->video_latency[1] = db[11];
    if (len >= 12)
        connector->audio_latency[1] = db[12];

    DRM_LOG_KMS("HDMI: DVI dual %d, "
            "max TMDS clock %d, "
            "latency present %d %d, "
            "video latency %d %d, "
            "audio latency %d %d\n",
            connector->dvi_dual,
            connector->max_tmds_clock,
          (int) connector->latency_present[0],
          (int) connector->latency_present[1],
            connector->video_latency[0],
            connector->video_latency[1],
            connector->audio_latency[0],
            connector->audio_latency[1]);
}

static void
monitor_name(struct detailed_timing *t, void *data)
{
    if (t->data.other_data.type == EDID_DETAIL_MONITOR_NAME)
        *(u8 **)data = t->data.other_data.data.str.str;
}

static bool cea_db_is_hdmi_vsdb(const u8 *db)
{
    int hdmi_id;

    if (cea_db_tag(db) != VENDOR_BLOCK)
        return false;

    if (cea_db_payload_len(db) < 5)
        return false;

    hdmi_id = db[1] | (db[2] << 8) | (db[3] << 16);

    return hdmi_id == HDMI_IDENTIFIER;
}

void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
{
    uint8_t *eld = connector->eld;
    u8 *cea;
    u8 *name;
    u8 *db;
    int sad_count = 0;
    int mnl;
    int dbl;

    memset(eld, 0, sizeof(connector->eld));

    cea = drm_find_cea_extension(edid);
    if (!cea) {
        DRM_DEBUG_KMS("ELD: no CEA Extension found\n");
        return;
    }

    name = NULL;
    drm_for_each_detailed_block((u8 *)edid, monitor_name, &name);
    for (mnl = 0; name && mnl < 13; mnl++) {
        if (name[mnl] == 0x0a)
            break;
        eld[20 + mnl] = name[mnl];
    }
    eld[4] = (cea[1] << 5) | mnl;
    DRM_DEBUG_KMS("ELD monitor %s\n", eld + 20);

    eld[0] = 2 << 3;        /* ELD version: 2 */

    eld[16] = edid->mfg_id[0];
    eld[17] = edid->mfg_id[1];
    eld[18] = edid->prod_code[0];
    eld[19] = edid->prod_code[1];

    if (cea_revision(cea) >= 3) {
        int i, start, end;

        if (cea_db_offsets(cea, &start, &end)) {
            start = 0;
            end = 0;
        }

        for_each_cea_db(cea, i, start, end) {
            db = &cea[i];
            dbl = cea_db_payload_len(db);

            switch (cea_db_tag(db)) {
            case AUDIO_BLOCK:
                /* Audio Data Block, contains SADs */
                sad_count = dbl / 3;
                if (dbl >= 1)
                    memcpy(eld + 20 + mnl, &db[1], dbl);
                break;
            case SPEAKER_BLOCK:
                /* Speaker Allocation Data Block */
                if (dbl >= 1)
                    eld[7] = db[1];
                break;
            case VENDOR_BLOCK:
                /* HDMI Vendor-Specific Data Block */
                if (cea_db_is_hdmi_vsdb(db))
                    parse_hdmi_vsdb(connector, db);
                break;
            default:
                break;
            }
        }
    }
    eld[5] |= sad_count << 4;
    eld[2] = (20 + mnl + sad_count * 3 + 3) / 4;

    DRM_DEBUG_KMS("ELD size %d, SAD count %d\n", (int)eld[2], sad_count);
}
EXPORT_SYMBOL(drm_edid_to_eld);

int drm_av_sync_delay(struct drm_connector *connector,
              struct drm_display_mode *mode)
{
    int i = !!(mode->flags & DRM_MODE_FLAG_INTERLACE);
    int a, v;

    if (!connector->latency_present[0])
        return 0;
    if (!connector->latency_present[1])
        i = 0;

    a = connector->audio_latency[i];
    v = connector->video_latency[i];

    /*
     * HDMI/DP sink doesn't support audio or video?
     */
    if (a == 255 || v == 255)
        return 0;

    /*
     * Convert raw EDID values to millisecond.
     * Treat unknown latency as 0ms.
     */
    if (a)
        a = min(2 * (a - 1), 500);
    if (v)
        v = min(2 * (v - 1), 500);

    return max(v - a, 0);
}
EXPORT_SYMBOL(drm_av_sync_delay);

struct drm_connector *drm_select_eld(struct drm_encoder *encoder,
                     struct drm_display_mode *mode)
{
    struct drm_connector *connector;
    struct drm_device *dev = encoder->dev;

    list_for_each_entry(connector, &dev->mode_config.connector_list, head)
        if (connector->encoder == encoder && connector->eld[0])
            return connector;

    return NULL;
}
EXPORT_SYMBOL(drm_select_eld);

bool drm_detect_hdmi_monitor(struct edid *edid)
{
    u8 *edid_ext;
    int i;
    int start_offset, end_offset;

    edid_ext = drm_find_cea_extension(edid);
    if (!edid_ext)
        return false;

    if (cea_db_offsets(edid_ext, &start_offset, &end_offset))
        return false;

    /*
     * Because HDMI identifier is in Vendor Specific Block,
     * search it from all data blocks of CEA extension.
     */
    for_each_cea_db(edid_ext, i, start_offset, end_offset) {
        if (cea_db_is_hdmi_vsdb(&edid_ext[i]))
            return true;
    }

    return false;
}
EXPORT_SYMBOL(drm_detect_hdmi_monitor);

bool drm_detect_monitor_audio(struct edid *edid)
{
    u8 *edid_ext;
    int i, j;
    bool has_audio = false;
    int start_offset, end_offset;

    edid_ext = drm_find_cea_extension(edid);
    if (!edid_ext)
        goto end;

    has_audio = ((edid_ext[3] & EDID_BASIC_AUDIO) != 0);

    if (has_audio) {
        DRM_DEBUG_KMS("Monitor has basic audio support\n");
        goto end;
    }

    if (cea_db_offsets(edid_ext, &start_offset, &end_offset))
        goto end;

    for_each_cea_db(edid_ext, i, start_offset, end_offset) {
        if (cea_db_tag(&edid_ext[i]) == AUDIO_BLOCK) {
            has_audio = true;
            for (j = 1; j < cea_db_payload_len(&edid_ext[i]) + 1; j += 3)
                DRM_DEBUG_KMS("CEA audio format %d\n",
                          (edid_ext[i + j] >> 3) & 0xf);
            goto end;
        }
    }
end:
    return has_audio;
}
EXPORT_SYMBOL(drm_detect_monitor_audio);

static void drm_add_display_info(struct edid *edid,
                 struct drm_display_info *info)
{
    u8 *edid_ext;

    info->width_mm = edid->width_cm * 10;
    info->height_mm = edid->height_cm * 10;

    /* driver figures it out in this case */
    info->bpc = 0;
    info->color_formats = 0;

    if (edid->revision < 3)
        return;

    if (!(edid->input & DRM_EDID_INPUT_DIGITAL))
        return;

    /* Get data from CEA blocks if present */
    edid_ext = drm_find_cea_extension(edid);
    if (edid_ext) {
        info->cea_rev = edid_ext[1];

        /* The existence of a CEA block should imply RGB support */
        info->color_formats = DRM_COLOR_FORMAT_RGB444;
        if (edid_ext[3] & EDID_CEA_YCRCB444)
            info->color_formats |= DRM_COLOR_FORMAT_YCRCB444;
        if (edid_ext[3] & EDID_CEA_YCRCB422)
            info->color_formats |= DRM_COLOR_FORMAT_YCRCB422;
    }

    /* Only defined for 1.4 with digital displays */
    if (edid->revision < 4)
        return;

    switch (edid->input & DRM_EDID_DIGITAL_DEPTH_MASK) {
    case DRM_EDID_DIGITAL_DEPTH_6:
        info->bpc = 6;
        break;
    case DRM_EDID_DIGITAL_DEPTH_8:
        info->bpc = 8;
        break;
    case DRM_EDID_DIGITAL_DEPTH_10:
        info->bpc = 10;
        break;
    case DRM_EDID_DIGITAL_DEPTH_12:
        info->bpc = 12;
        break;
    case DRM_EDID_DIGITAL_DEPTH_14:
        info->bpc = 14;
        break;
    case DRM_EDID_DIGITAL_DEPTH_16:
        info->bpc = 16;
        break;
    case DRM_EDID_DIGITAL_DEPTH_UNDEF:
    default:
        info->bpc = 0;
        break;
    }

    info->color_formats |= DRM_COLOR_FORMAT_RGB444;
    if (edid->features & DRM_EDID_FEATURE_RGB_YCRCB444)
        info->color_formats |= DRM_COLOR_FORMAT_YCRCB444;
    if (edid->features & DRM_EDID_FEATURE_RGB_YCRCB422)
        info->color_formats |= DRM_COLOR_FORMAT_YCRCB422;
}

int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)
{
    int num_modes = 0;
    u32 quirks;

    if (edid == NULL) {
        return 0;
    }
    if (!drm_edid_is_valid(edid)) {
        dev_warn(connector->dev->dev, "%s: EDID invalid.\n",
             drm_get_connector_name(connector));
        return 0;
    }

    quirks = edid_get_quirks(edid);

    /*
     * EDID spec says modes should be preferred in this order:
     * - preferred detailed mode
     * - other detailed modes from base block
     * - detailed modes from extension blocks
     * - CVT 3-byte code modes
     * - standard timing codes
     * - established timing codes
     * - modes inferred from GTF or CVT range information
     *
     * We get this pretty much right.
     *
     * XXX order for additional mode types in extension blocks?
     */
    num_modes += add_detailed_modes(connector, edid, quirks);
    num_modes += add_cvt_modes(connector, edid);
    num_modes += add_standard_modes(connector, edid);
    num_modes += add_established_modes(connector, edid);
    num_modes += add_inferred_modes(connector, edid);
    num_modes += add_cea_modes(connector, edid);

    if (quirks & (EDID_QUIRK_PREFER_LARGE_60 | EDID_QUIRK_PREFER_LARGE_75))
        edid_fixup_preferred(connector, quirks);

    drm_add_display_info(edid, &connector->display_info);

    return num_modes;
}
EXPORT_SYMBOL(drm_add_edid_modes);

int drm_add_modes_noedid(struct drm_connector *connector,
            int hdisplay, int vdisplay)
{
    int i, count, num_modes = 0;
    struct drm_display_mode *mode;
    struct drm_device *dev = connector->dev;

    count = sizeof(drm_dmt_modes) / sizeof(struct drm_display_mode);
    if (hdisplay < 0)
        hdisplay = 0;
    if (vdisplay < 0)
        vdisplay = 0;

    for (i = 0; i < count; i++) {
        const struct drm_display_mode *ptr = &drm_dmt_modes[i];
        if (hdisplay && vdisplay) {
            /*
             * Only when two are valid, they will be used to check
             * whether the mode should be added to the mode list of
             * the connector.
             */
            if (ptr->hdisplay > hdisplay ||
                    ptr->vdisplay > vdisplay)
                continue;
        }
        if (drm_mode_vrefresh(ptr) > 61)
            continue;
        mode = drm_mode_duplicate(dev, ptr);
        if (mode) {
            drm_mode_probed_add(connector, mode);
            num_modes++;
        }
    }
    return num_modes;
}
EXPORT_SYMBOL(drm_add_modes_noedid);